The capacity for rationality is innate, but also variable due partly to innate factors, just like virtually all psychological capacities and tendencies. All people can be taught and trained to be better at rationality and to place more value on trying to apply those rational skills. However, some people are born being better at it and better at getting better at it via education. Education actually tends to enhance innate differences between individuals rather than make them more similar. A standard saying in research on basic cognitive skills is "rich get richer", meaning that those who start out with more of the skill also tend to improve that skill via training at a faster rate. Obviously individuals also differ in how much training they get, so a person with more innate skill can wind up with less skill than someone who got much more training to develop their skill.
We use the term ‘rational’, to mean three different things.
First, to speak of a species-wide characteristic of Homo Sapiens: Man is a rational being. This use refers to the ability of normal individual human beings to express their views in a rational way.
Then we can also use the term ‘rational’ to characterise a particular expression of somebody’s views. Somebody’s explanations can be rational or not. An argument will be rational or not.
Thirdly, we can use ‘rational’, or in fact more often ‘irrational’, essentially as a criticism of other people, normally for expressing their view(s) in a way we deem irrational.
Thus, each normal member of the human species can be both rational as to their ability and irrational as to a particular expression of their views, just on one occasion or regularly.
In the first sense, rationality is a general characteristic of all human beings. Only a small percentage of the human population don’t have any ability to express their views in a rational way.
In the third sense, expressing oneself in a rational manner is best understood as either a conscious choice or the result of an unconscious process. This will account for the vast majority of views being deemed irrational, although often somewhat unfairly.
But all of that variability in how much each person is capable of rational thought isn't likely to explain much of the variability in when and who actually engages in rational thought on a topic, and why people given the same info disagree on political issues. Most of that variance is not due to rational skill but rational will, the choice to apply one's reasoning skills to the issue rather than just rationalize and defend whatever claim serves ones political objectives. The other major source of variance is differences in basic values that determine one's political objectives.
The main variability is due to either a conscious choice or the result of an unconscious process (third sense).
If it is a conscious choice, there’s no good reason to assume ipso facto it must be irrational.
As I see it, using an irrational argument is similar to resorting to a lie. A lie doesn’t make the liar irrational. In fact, lying may be the more rational thing to do. An attitude that the liar could conceivably explain in a rational way (I lied because I was in danger of my life).
If it is unconscious, and it may be more often largely unconscious, it may work like language itself. We’re usually not entirely conscious of why we say what we say, even when we deliver a top-notch rational explanation. Rather, it comes out as such. We would typically be conscious of some aspects of why we say what we say, not of all aspects. And then, there would be no difference in this respect between rational and irrational expression.
Thus, opting, somehow, for an irrational expression may be the optimal thing to do and it could be your unconscious supervising your apparent choice.
Experiments where people contradict their own knowledge can then be understood as driven by the interaction between subject and observer. The subject may have a grudge, or some negative bias, against people like the observer, and consciously or unconsciously select an expression that will be seen as irrational by the observer, although it may well be more like a lie, but perfectly rational lie. If so, the observer shouldn’t expect to be able to elicit from the subject a rational account of why they elected to give an irrational expression. Instead, the rational thing to do for the subject will be to keep up the pretence, just like a liar won’t necessarily admit to have lied to you just because you are asking.
Rationality is normally associated both with logic and with verbal expression. Even rational thoughts are supposed to be linguistically framed. Yet, this may be a bias of our linguistic mind and of language as essentially a system of interpersonal and social communication. Our non-verbal rational mind never had a say and its very existence got lost in our communication process.
So, I see the ‘scientific’ view on rationality as affected by communication, cultural and observational biases and unable to account for the facts.
Take human-influenced climate change for example. What is the cause of differences in opinion about whether its happening?
As with evolution, the facts supporting that it is happening are so clear and widespread that it is implausible that any denier reached that position honestly via applying reasoning to the best of their ability. So denial is almost always the result of concerted efforts to violate honest reasoning in order to reach a preferred conclusion. Theological and economic biases are the source of that bias to deny climate change. But not all people who accept climate change arrived at that conclusion rationally either. Some did, but some happen to hold the scientific position, but because they have an ideological bias toward wanting to believe it. Proposed solutions to the problem of climate change entails restricting most of the ways that the rich have gotten rich, and people limiting their consumption, including not eating animals, etc.. Thus, people who have other emotional or ideological reasons to favor such changes, have a biased reason to believe in climate change, and would likely believe it even if the science didn't support it. Of those who accept climate change purely for rational, scientific reasons, some may actually share the same values as either the irrational deniers or irrational accepters, but they value being rational even more so they accept it even though it creates an obstacle for some of their other political objectives. In sum, applying rational thought is most often a result of an interaction between what one's goals are, how much you value rationality in principle, and which conclusion happens to be supported by rational thought.
I see climate-deniers, for example, as possibly rational people electing, somehow, to defend their view in a rational manner. So, how to explain the difference with the climatologists’ near unanimous view?
First, as we have already agreed, many people simply won’t have the information. They will argue rationally from the wrong premises.
Second, some people just do it in the same way that they would tell lies. And it may well be, most of the time, the rational thing to do. In particular, if you have vested interests in the oil or coal industry for example, you may elect to deny that climate change is caused by human beings and that would be the rational thing to do. For some people, it will be more like an actual lie, if they are conscious of why they deny climate change. Other people will do it without really being aware of what they are doing, but still that will be the optimal thing to do, given their personal knowledge and options in life, like short term personal benefit against caring for future generations.
EB